Homemade Color Wheel TV - Videokarma.org TV - Video

Steve K · #1 10-18-2003, 08:43 PM

I have been debating for some time if I was going to post one of my latest projects on this site in fear of all of you thinking I was completely nuts but seeing that there is this new section I figured what the heck.

After seeing a working color wheel TV at Steve McVoy's museum I wondered if I could build one. I have been planning to do this for some time but never thought that they would really work. Here are some pictures of my attempt. I made the color wheel from two thin pieces of Plexiglas with the filters in between. The TV is an old Coronado. The converter chassis I built from plans in a 1956 Radio Electronics magazine. Steve has given me a lot of advise and encouragement but I do not have it working yet. Lately I have been too busy with other things to work on it but hopefully I can get back to it soon.

Steve

Steve K · #2 10-18-2003, 08:44 PM

Back of the set

Steve K · #3 10-18-2003, 08:46 PM

color chassis

#4 10-18-2003, 09:08 PM

Thats really cool and a nice custom cabinet. What chassis did the article use. Any possibility of posting the article. Reason I ask is because my father once told the story when around 1955 he bought a color wheel kit and installed it to an RCA 630 chassis. He said he never did get it working but used it for a while wathcing in B&W. Now that he thinks about it there may not have been any color transmissions at the time.

Paul

Rob · #5 10-18-2003, 09:10 PM

SteveK,

Let me be the first here to congratulate you on your enterprise. That is fantastic! My only advice I can think of is to suggest you use a 10FP4 or if a 12" CRT use whatever the aluminized one is as you will really appreciate the extra brightness due to the terrific loss through the filter wheel.

I was thinking also of doing such a project but want to make mine with the RGB filters on a drum where the CRT is inside the drum. I figure I can get a larger display in a smaller cabinet that way, and the picture can be centered in the cabinet like a normal set.

It looks like you are very close to getting this project operational. Please keep us posted!

Steve D. · #6 10-19-2003, 09:43 PM

I've been to Steve K's home and seen this little beauty in operation. It's a really slick professional job. I think with just a few adjustments Steve will have a glorious color picture. That color wheel really gets going!

Haoleb · #7 10-19-2003, 11:53 PM

this is the first time i have ever seen such a device!

Ive never really browsed these forums but this is quite intersting. Im guessing that the color wheel spins really fast therefore giving color picture. although i cant understand how it works. Intersting though!

Steve K · #8 10-21-2003, 08:06 PM

Steve D: Thank you for the kind words. If I ever get it working you will need to be my witness here on the forum.

Haoleb: The wheel spins at 600 RPM. The NTSC color signal is converted into a field-sequential signal thus providing the red info, then green, then blue.

Rob: I am using a 10FP4. The wheel does cut down on the brightness but it is still bright enough to watch with normal room lighting. I did not use that tube by design though, it was the only one I had on hand! A color drum set would be interesting but if you used an old CRT it would have to be fairly big. Also mounting the CRT assembly and the drum assembly would be a challenge. However, I too can have the picture in the middle of the cabinet, all I need to do is stick a big extention out on the left side to hold the radio and phonograph!

Paul: The magazine article was the same as the Colordaptor that was available at the time. One could buy the wheel and coils but I don't think that the entire thing was available in kit form although I could be wrong. If you'd like I can mail you a copy of the article. I'm not sure of the legalities of posting it here.

Steve

Marlin Mackley · #9 10-23-2003, 08:52 AM

Way to go Steve K! You know, I have lately had a wild idea to, in my spare time (HAH!) to use one of those 24 inch steel Dumont CRT's and a large color wheel, along with some kinda converter to build a HI DEF set. Certainly the scan could be run at any shape, size and line count you want. Anybody want to tackle THAT one??

Marlin

Steve D. · #10 10-23-2003, 10:15 AM

Marlin,
One of the reasons sequential color tv was impractical was that with increased screen size the wheel also had to increase in diameter, Your proposed 24" screen set would require an extremely large color wheel. In fact if that baby with its aircraft powered motor got loose, Fenton, Mo. would have a very long ditch thru it starting at your house.

kc8adu · #11 10-23-2003, 04:58 PM

you could cut slots in ceiling and floor for the wheel!
put some blades on it and use it to replace the hvac blower!

Marlin Mackley · #12 10-26-2003, 08:01 AM

"..if that baby with its aircraft powered motor got loose, Fenton, Mo. would have a very long ditch thru it starting at your house..."
My mom always did say I would wind up diggin' ditches!

Marlin

#13 10-28-2003, 04:13 PM

HI Steve,
Thanks for the article. I emailed it to my father and here is an excerpt of his reply.

Quote:

That article was written in 1956, my first year at Drexel.
I must have bought the RCA 630 a year or two before that because I didn't have time to play with electronics while in college.

The article I found was in Popular Electronics I think. At that time, say 1954, the CBS system had been adopted by the FCC but only experimental broadcasts were being made at that time, maybe an hour a day. The CBS system used three picture signals simultaneously or something like that and took much more bandwidth, say two or three times and was not compatable with the NTSC B/W signal. The country was not ready to throw out their black and white sets.

Since the CBS system was never broadcast to the public, I lost interest and I doubt that I could have ever built the color convertor anyway without test equipment. And the mechanical color wheel was hard to make, being almost three feet in diameter.

The article you sent is very interesting. I never knew anyone thought of using the NTSC color signal to drive a color wheel over a black and white picture tube. Of course, it should work although the colors may not be as fast as a color tube. Most of the NTSC signal is luminance which gives the resolution for fine detail with the color being a small part of the signal at low resolution.

That article attemps to decode the color after the B/W set tunes the station. then applies the color signals to the tube in synchronism with the color wheel.

But if you wanted to try it with one of your small B/W tubes, you could use a color chassis which already has all the color demodulation and delay lines built in with the output being three RGB signals to apply to the color guns. So all you really have to build is that tritch triode circuit (tri-stable switch V4a,b V5a,b) to switch the Red, Blue and Green signals to the monochrome tube gun. Then follow it with the two-tube synchronizing circuit (V7 and V8) for controlling the color wheel. Of course build a color wheel and motor also. Would be an interesting project for a 5-inch TV.

Interesting he mentions a 5 inch tube. He's probablly thinking about one of my 5AXP4 or 8XP4 test tubes. Since I thought about the possibility of a standard CRT not being bright enough I thought using an early projection crt directly viewed would give the brightness.

Take care,

Paul

Steve K · #14 03-20-2004, 09:17 PM

I thought that I would post an update on my color wheel project. It does not work yet but I think that I am getting closer. The converter chassis has been aligned. I now have to realign the TV chassis to pass the color signal through the video.

I continued to work on the cabinet as can be seen in the picture. I figured that if I never get it to work it will at least it will look better when it's sitting in the dump!

#15 03-20-2004, 10:10 PM

Looking good Steve! How can you talk about that ending up in a dump??????? Will it to the museum so that it'll be preserved.

Anthony